According to statistics, a misplaced impaction of the first molar tooth of the upper jaw and an impaction of the second molar tooth of the lower jaw occur in approximately 3% of the world's population. When a patient receives a correction treatment, the first molar tooth of the patient's lower jaw may incline backward due to an anchorage preparation, the problem of the tooth itself, or an insufficient arch length, such that the second molar tooth may be misplaced or impacted.
In general, a traditional way of treating an inclined molar tooth uses a brass wire to shift the first molar tooth towards a distal side (which is a rear end of the tooth socket) or an elevator to upright a molar tooth, if the situation is not too serious. As dental technologies advance, steel wire or band is used for uprighting and correcting a molar tooth.
Clinically, it is common to see an eruptive and impacted first molar tooth, which causes damages to periodontal tissues, decays to teeth, and adverse effects on the integrity of a dental arch. Since it is not easy to keep the area of the first molar tooth dry, the correction rest may be stuck, and thus making the installation of the correction band difficult.
In view of the foregoing shortcomings of the prior art, the inventor of the present invention has developed a long-arm type upright molar tooth spring made of a simple circular stainless steel wire, and adopting a first type of the principle of lever to overcome the difficulty of keeping the first molar tooth dry and prevent the correction rest from getting stuck. In clinical practices, we can see significant uprighting effects within two to five weeks depending on the inclination of the molar tooth, and the related technology has been disclosed in details in U.S. Pat. No. 5,720,611.
However, it will be easy to hurt a patient's tissues during the process of wearing the steel wire according to the aforementioned patent, if a dentist is not experienced. Obviously, such patented invention requires further improvements.
The inventor of the present invention further developed an improved long-arm type upright molar tooth spring extended into and fixed to an adjacent side between engaging surfaces of a normal tooth and an inclined tooth for uprighting the inclined tooth.